This invention relates to a device for straightening bridges which have had their lower girders bent by trucks passing underneath with loads higher than the clearance afforded by the bridge.
When trucks with illegal high loads pass under bridges, whether they be railroad, vehicular or pedestrian bridges, the load smashes into the lower bridge beams which results in the lower beams being bent. As the resulting impact bends the lower beams out of alignment and consequently weakens the bridge. This is a growing problem as there are more and more trucks on the road and the sizes of them is growing to such an extent that they barely fit on the road. Part of the growth has been vertical as well as length and in breadth. As the vehicles are limited by lane widths in their breadth and by state and federal laws in their length, already up to 57 feet on interstates, the trailer portions of them have gotten higher. While the normal enclosed trailer truck is built so that the top of the trailer just gets under the Federal standards for interstates those trucks with flatbeds carry all kinds of loads which are not necessarily in compliance with height standards. With the number of trucks growing enormously and the state police contingent of most states static the potential for bridge damage due to unchecked high loads has grown considerably. Truckers too avoid highway inspection stations and go down back roads if they know they have a load that is too high. In short, truckers have become a menace on the roads and the height problem is one manifestation of that situation.
Heretofore, when bridge beams were bend, there was no simple way to correct it. In most cases the beams had to be actually removed and replaced. With the instant invention, a beam can be straightened in place thus eliminating a lost of costly work by highway departments and contractors.
The instant invention contemplates using a threaded rod with two clamping members to engage both the bent beam and a rigid part of the bridge to as to gradually bend the beam back into alignment by rotating a nut portion on the rod so as to turn the rod and allow one clamping member to move slowly along the rod. As most bridge beams have a flange on them, being either I-beams or similar beams, the clamping members have a portion designed to engage the flange area and thereby allow firm engagement of the beam by the straightening device.
The clamping member which engages the fixed structural portion of the bridge has a cross pin with a ball and socket arrangement therein, the ball and socket being machined into the cross pin thereby fixing the end of the rod in place. The opposite clamping member which engages the bent beam has a cross pin with an apeture drilled therein and tapped with threads so as to allow it to move along the threaded rod as it is turned. Thus, as the threaded rod is turned the mechanical advantage created by the cross pin will cause the beam to be manipulated back into its original position. The invention is used with several others to gradually move the beam back into place. If the beam is large enough, it will be heated as the pressure is gradually exerted by the turning of the nuts on the ends of the multiple straighteners.
The straighteners are designed to be adjustable both in the clamping members for any size beam and the length of the rods can be increased. Several different length rods are contained with a pair of clamping members. The diameter of the rods and holes in the clamping members will also vary depending on the size of the beams to be bent back into shape.
Having described the invention, the following objects of this invention are hereby enumerated.
It is an object of this invention to provide a bridge beam straightening device which can make the repair of bridges much easier and less expensive,
It is a further object of this invention to provide a bridge beam straightening device which employs two clamping members and a tensioning device to close the distance between them to allow gradual straightening of a bridge beam.
It is a still further object of this invention to provide in a bridge beams straightening device a clamping device with a ball and socket arrangement so as to all a threaded rod to be turned and the clamping device remain in place.
Another object of this invention is to provide a novel and unique method of straightening bent bridge members and beams.
A still further object of this invention is to provide a novel group of straightening devices which can be used in tandem to straighten a bridge.